The culprit seems to be a combination of dry air and also the storm's very fast forward speed, which is keeping the core structure from solidifying. Ernesto is blasting W at over 20 kt, and already halfway across the Caribbean!

Given this, iCyclone has decided not to chase Ernesto on the Yucatan. Of course we're disappointed, as the Yucatan is our favorite place to chase hurricanes—but this is good news for residents of Quintana Roo! While there's a chance the storm might restrengthen as it approaches the Peninsula, the threat is not great enough to justify a chase expedition.

However... There are some hints that the cyclone might come back to life in the Bay of Campeche, after crossing the Yucatan. But that's a long way off. For now, we'll just watch Ernesto from the sidelines.